The issue is not whether experts know the rules. Most do. The issue is whether the report shows that those rules have been applied.
Part 35 of the Civil Procedure Rules is clear. Expert evidence must be restricted to what is required to resolve the proceedings. The expert’s duty is to the court, and that duty overrides any obligation to the person who instructs or pays them. Practice Direction 35 reinforces the same discipline: expert evidence should be independent, objective and uninfluenced by litigation. Experts must not act as advocates. They must consider all material facts, including those that may weaken their opinion.
Independence must be visible. A poor report is often one where the conclusion feels predictable from the source of instruction. A claimant report that accepts every symptom without analysis is a problem. A defendant report that treats every inconsistency as exaggeration is also a problem. Independence does not mean splitting the difference between the parties. It means reaching a reasoned view that belongs to the expert.
That view may support the claimant, the defendant, or neither side. What matters is that the expert has applied their own judgement to the evidence.
A persuasive report does more than record the claimant’s account, list documents and state a conclusion. It explains the reasoning. What facts support the opinion? What facts create difficulty? What alternative explanations were considered? What assumptions were made? What lies outside the expert’s expertise? A report that avoids those questions may be convenient, but it is not persuasive.
The real test of independence is how the expert deals with difficult facts. In personal injury claims, may include previous symptoms, delayed treatment, inconsistent accounts, normal imaging, surveillance evidence or a longer recovery period than expected. In clinical negligence cases, it may include recognised complications, uncertain causation, incomplete records or disputed factual assumptions.
The expert does not have to change their opinion every time an awkward fact appears. They do have to engage with it. A report that ignores difficult material invites attack. A report that acknowledges it and explains why it does or does not alter the conclusion is far stronger. It shows the court that the expert has not acted selectively.
This is particularly important because medico-legal cases involve subjective symptoms, including pain, psychological injury, fatigue, dizziness and functional limitation. That does not make them unreal. It does mean the expert must test the account against the records, examination findings and wider evidence. The expert’s role is not to believe or disbelieve by instinct. It is to explain whether the presentation is medically plausible.
Experts must avoid drifting into advocacy. This can happen subtly. An expert may adopt the language of the instructing party, treat disputed facts as established, dismiss alternative explanations too quickly or express views on credibility that go beyond their role. They may argue the litigation case rather than address the medical issue. That is where independence begins to fail.
An expert can say that an account is inconsistent with the records, that symptoms have lasted longer than expected, that causation is unsupported, or that more evidence is needed before a firm opinion can be given. What they should not do is dress speculation as certainty or make findings that belong to the court. Dishonesty is not a medical diagnosis. Liability is not a clinical opinion.
A good expert stays within their field. A spinal surgeon should not offer psychiatric opinion. A psychiatrist should not determine accident reconstruction. A GP expert should recognise when specialist evidence is needed. Identifying the limits of expertise usually makes a report more credible, not less.
Medico-legal reporting also has an efficiency problem. High-volume personal injury work can encourage short reports, standard paragraphs and rapid turnaround. Proportionality matters, and a low-value claim does not always require a lengthy report. But speed becomes dangerous when it replaces thought. A short report still needs a reasoned opinion. A fixed-fee report still needs independence.
This is especially important in whiplash, low-speed impact and soft tissue injury claims. These cases may appear routine, but they often involve disputed causation, previous symptoms, inconsistent histories and contested duration. If the issue is straightforward, the report can be concise. If the issue is disputed, the reasoning must be strong enough to withstand scrutiny.
Judicial scrutiny cuts both ways. Poor expert evidence can come from either side. A claimant expert may overstate causation. A defendant expert may understate the effect of an accident. The problem is not the side. It is the loss of independence.
Those who instruct experts also affect the quality of evidence. Poor instructions create poor reports. Solicitors and claims handlers should identify the real issues: causation, pre-existing symptoms, inconsistent records, prognosis or limits of expertise. Clear instructions protect both the expert and the court process.
Independence is not anti-commercial. The market does not need experts who always say yes. It needs experts whose opinions can be relied upon when tested. An uncomfortable opinion may be more useful than a supportive report that collapses later. There is commercial value in credibility.
The expert declaration is not a magic spell. It does not cure selective reasoning, unsupported conclusions or advocacy. The report must earn the declaration. The future of medico-legal reporting will belong to experts whose evidence can withstand scrutiny because it is independent in substance, not merely compliant in form.
